Top 5 fixes to your LMTV

[hike]

deleted–

 

[GeneralDisorder]

Works for me. I'm not using Cat service anymore. Can you send me you shipping info? My business email is *deleted*. I'm the owner

I'll send you a PM - probably shouldn't post your email in open forum for bots to scrape it and add you to mail lists.

 

[hike]

The kneeling hydraulic cylinders could be repurposed/replaced with cylinders to do something else useful, such as extend an awning, deploy stairs, or lift a fuel can rack.

Has anyone tried using the hydraulic kneeling cylinders to level the vehicle when parked?

 

[DTinNC]

Your truck is the 3126b engine?

It's not illegal to flash it to the 330 HP map - you can pay CAT corporate for a "rerate" if you talk to the right people. Or you can send me your ECM and I can do it for $600 and also change any other features like turning on cruise control, and correcting for ECO hubs or 3.07 gears, etc. Often I find that the CAT people are unfamiliar with our trucks and either unwilling to touch them, or they screw it up - I have found that a fair number of these trucks - especially the 3126b trucks will not accept a flash though the truck's wiring harness and when that happens the CAT dealer will likely have no choice but to make you buy a new ECM programmed by corporate for $3k because they are not equipped to bench flash an ECM outside of the truck. And when that happens it wipes the ECM and the truck is a lawn ornament till you get a replacement. This can be corrected if you pull the ECM and use bench flashing tools but again - dealers are not equipped for that level of service.

The only hardware modification the 3126b requires for the 330 HP tune is adding the atmospheric pressure sensor. There's already a harness connector present for it. You just screw it into the port on the engine and plug it in. Takes 10 minutes. Turbo and injectors and all that are identical. You are just changing the tune to the MTV map.

The 370 HP map is for the C7. Same rules apply as above but it doesn't require the sensor - all C7's already have it. The C7 can be rated at 275, 330, or 370 HP all using the same hardware.

Appreciate all the info. What can be reasonably done to a 3116 (1994 M1081 variant)? I also have new 3.07 gears for the diffs to install. Thank you

 

[GeneralDisorder]

Appreciate all the info. What can be reasonably done to a 3116 (1994 M1081 variant)? I also have new 3.07 gears for the diffs to install. Thank you

Forget the 3.07 gears. Waste of time - get ECO hubs.

The 3116 is getting really old and tough to find parts for. You can upgrade to the 290 HP fueling parts, and swap over to the 3126/C7 turbocharger - the Borg Warner S300. Should get you up to about 300 HP. I wouldn't take the 3116 truck engine past that. The Marine variants were higher rated but had a completely different cylinder head that is not truck compatible.

 

[DTinNC]

Forget the 3.07 gears. Waste of time - get ECO hubs.

The 3116 is getting really old and tough to find parts for. You can upgrade to the 290 HP fueling parts, and swap over to the 3126/C7 turbocharger - the Borg Warner S300. Should get you up to about 300 HP. I wouldn't take the 3116 truck engine past that. The Marine variants were higher rated but had a completely different cylinder head that is not truck compatible.

10-4 thank you

 

[Ronmar]

You can Easily get 350HP out of your 3116. Start with the 290HP governor and turbo modifications general mentioned. Then turn the high speed screw up to allow 2800RPM and delete the air compressor, alternator, power steering and cooling fan...

I believe the marine engine is basically the same it is simply tested/rated under a different standard than a road engine with its necessary sub systems installed. That's where the 50HP are going, for testing the marine variant is only driving a water pump so of course it has more available HP...

 

[DTinNC]

You can Easily get 350HP out of your 3116. Start with the 290HP governor and turbo modifications general mentioned. Then turn the high speed screw up to allow 2800RPM and delete the air compressor, alternator, power steering and cooling fan...

I believe the marine engine is basically the same it is simply tested/rated under a different standard than a road engine with its necessary sub systems installed. That's where the 50HP are going, for testing the marine variant is only driving a water pump so of course it has more available HP...

The deletes may affect driveability. . Thank you. Definitely looking into redoing the cooling system mods that you referenced elsewhere. My 3116 typically runs around 175ish degrees.

 

[MatthewWBailey]

Forget the 3.07 gears. Waste of time - get ECO hubs.

I second that sentiment. I started with 3.07s. It still
Had to redline to do 70. Now I'm swapping 3.90s back in (with lockers) since I put the ECO hubs on there. I'm driving at 70mph at 1400 rpm. Got 9mpg last tankful of mixed city/highway.

 

[DTinNC]

I second that sentiment. I started with 3.07s. It still
Had to redline to do 70. Now I'm swapping 3.90s back in (with lockers) since I put the ECO hubs on there. I'm driving at 70mph at 1400 rpm. Got 9mpg last tankful of mixed city/highway.

Good to know thanks. Are the lockers full time or selectable?

 

[MatthewWBailey]

Good to know thanks. Are the lockers full time or selectable?

I purchased the Meritor Detroit locker product. Western Canadian Rockwell sells them. From feedback on here they apparently work without issue. I took one apart and it's clear to me that these devices "unlock" without worrying about engine torque applied. It's a pretty slick device. Only differential wheel torque makes it unlock via the cams. I calculated the differential torque required to thrust the cams apart and it's about 45lb-ft, that's the effect of the K value of the pre load springs.

 

[Ronmar]

Mmmm locker mmmmm...

 

[MatthewWBailey]

Mmmm locker mmmmm...

Good Bad or Ugly?

 

[Ronmar]

Good Bad or Ugly?

Well if it keeps me from digging a hole and having to get out and rig a line and winch, I like it. I may add one to the rear at some point. If you don't mind saying, what did that little gem set you back?

 

[MatthewWBailey]

Well if it keeps me from digging a hole and having to get out and rig a line and winch, I like it. I may add one to the rear at some point. If you don't mind saying, what did that little gem set you back?

They're still $1,118 plus shipping. I got 2

MERITOR DIFFERENTIAL LOCKER

New Meritor Differential Locker for FMTV/LMTV/MTV For Meritor RF611 Axles 32 Spline Based off of the Detroit Locker design Great when adding highway gears to your truck Locker fits the following: Axle Models: 611, RF19 and RF14 with 32 Splines M1078, M1079, M1080, M1081 2.5 Ton Trucks M1083...

westerncanadianrockwell.ca

 

[hike]

We have front and rear lockers in our Wrangler and have only used them while 'wheeling' with others. Hauling our offroad trailer to boondocking sites we are in 4wheel high and some times 4wheel low, though we have never needed the lockers on the way in or out pulling the trailer.

When we have had our M1078A1 offroad the traction issues seem related to the weight distribution between the axles. If we balance her well with the habitat I am thinking we won't need lockers to get into camp and back home—

 

[MatthewWBailey]

We have front and rear lockers in our Wrangler and have only used them while 'wheeling' with others. Hauling our offroad trailer to boondocking sites we are in 4wheel high and some times 4wheel low, though we have never needed the lockers on the way in or out pulling the trailer.

When we have had our M1078A1 offroad the traction issues seem related to the weight distribution between the axles. If we balance her well with the habitat I am thinking we won't need lockers to get into camp and back home—

I've observed that only in snow do I need something more, which is similar to other vehicles I've owned. This truck struggles in snow even with aired down tires on flat trails. Snow, especially the cold fine stuff, has no weight or friction, & nothing for tires to grab onto. So one side will always start spinning. Add a little incline and it'll just sit there and spin.

 

[hike]

I've observed that only in snow do I need something more, which is similar to other vehicles I've owned. This truck struggles in snow even with aired down tires on flat trails. Snow, especially the cold fine stuff, has no weight or friction, & nothing for tires to grab onto. So one side will always start spinning. Add a little incline and it'll just sit there and spin.

Grew up in Utah, I know what you mean. I have assumed we would need chains for snowy conditions. Too bad we can't repurpose our old rubber into studded snow tires—

 

[MatthewWBailey]

Grew up in Utah, I know what you mean. I have assumed we would need chains for snowy conditions. Too bad we can't repurpose our old rubber into studded snow tires—

I have a rear set of chains for drop dead emergencies. Never used them but I'd say this truck with full lockers and full chains could handle 2' of snow